Wear resistant garments and method and composition for production thereof

ABSTRACT

SHIRTS HAVING INCREASED WEAR LIFE ARE PRODUCED BY A METHOD COMPRISING SELECTIVELY TREATING THE SHIRT COLLAR AND NECK BAND WITH A COMPOSITION COMPRISING A NONAQUEOUS SOLUTION OF A POLYURETHANE POLYMER OR PRE-POLYMER WITH A FLUOROCARBON OIL REPELLANT AND SOIL RELEASE AGENT. THE TREATED COLLAR IS PRESSED AT ELEVATED TEMPERATURES TO CAUSE THE SITU POLYMERIZATION OF THE COMPOSITION THEREBY RESULTING IN A PERMANENT BOND BETWEEN THE SURFACE FIBERS OF THE SHIRT COLLAR AND THE POLYMERIZED COMPOSITION.

United States Patent 3,763,078 WEAR RESISTANT GARMENTS AND METHOD AND COMPOSITION FOR PRODUCTION THEREOF William E. Aldrich, Cranston, R.I., assignor to Warnaco Inc, Bridgeport, Conn. No Drawing. Filed Nov. 30, 1970, Ser. No. 93,804 Int. Cl. C08c 11/28, 11/32 US. Cl. 26033.4 F 7 Claims ABSTRACT OF THE DISCLOSURE Shirts having increased wear life are produced by a method comprising selectively treating the shirt collar and neck band with a composition comprising a nonaqueous solution of a polyurethane polymer or pre-polymer with a fluorocarbon oil repellant and soil release agent. The treated collar is pressed at elevated temperatures to cause the in situ polymerization of the composition thereby resulting in a permanent bond between the surface fibers of the shirt collar and the polymerized composition.

This invention relates to a composition and method useful in the manufacture of wearing apparel and the products derived therefrom. More particularly, this invention relates to a composition and method for enhancing the wear-resistance of selected garment parts such as shirt collars, neck bands and the like thereby producing novel garment parts.

It has long been recognized that the useful life of garments tends to be limited by the wear resistance of those parts of the garment, such as the collar, neck band and cuffs, which maintain the most intimate and continuous contact with the body. Such shirt components exhibit a tendency to ball or pill, stain and otherwise discolor thereby rendering the entire shirt useless to the wearer. The above problems have been found to be particularly acute in shirts manufactured from fabric blends including synthetic fibers. The shorter length staple fiber employed to manufacture such shirt fabrics exhibit a greater tendency to pill and to absorb oil-borne soil which causes permanent discoloration of the fabric.

Attempts have been made to solve the above problems by adding a layer of polymeric material to the shirt fabric in order to bond the uppermost fibers of the fabric surface and increase abrasion resistance. However, the use of polymeric materials has been limited by the requirement that they be capable of flowing into the shirt fabric at temperatures which will not damage the fabric; that they be durable to multiple launderings without extraction, creasing and cracking or delamination from the fabric; and that the physical or physical/chemical structure of the shirt remain the same during wear and laundering. Past attempts to product a commercially acceptable shirt using polymeric materials have not been successful since they failed to meet the above requirements. More particularly, the use of such materials has caused unacceptable levels of fabric stiffness and has aggravated the problem of oilborne soil absorption.

It is an object of this invention to provide a novel composition for treating shirt fabrics to increase their wearlife.

It is another object of the invention to provide a novel method for selectively treating shirt fabrics, and particularly shirt collars and necks bands, to enhance their wear-life without adversely elfecting the required physical and chemical characteristics of the fabric.

Yet another object of this invention is to produce novel wear resistant garments and garment parts such as shirt collars and neck bands.

3,763,078 Patented Oct. 2, 1973 ice The present invention resides in the discovery of novel compositions which are stable non-aqueous solutions of compounds which when employed in accordance with method aspects of the invention, produce garment components having a significantly enhanced wear-life while retaining acceptable physical and chemical properties. In accordance with method aspects of the invention, a garment, preferably one formed from a fabric blend including synthetic fibers, is selectively treated with the novel composition of the invention and thereafter subjected to processing steps which cause polymerization and permanent impregnation of the garment fabric thereby resulting in the formation of a novel wear and stain resistant garment.

The novel compositions of the invention comprise a non-aqueous solution of a polyurethane pre-polymer or a low molecular weight, partially polymerized polyurethane with compounds which exhibit the ability to repel the absorption of oil and to release soil when combined with synthetic and cellulosic fabrics or blends thereof. These compositions are employed in a method which results in the permanent combination of the composition with the fabric as the result of selective spraying and in situ polymerization. It has been discovered that both the formation of non-aqueous solutions and the use of low molecular weight polyurethane polymers or preferably polyurethane pre-polymers is critical to the production of commercially acceptable wear and stain resistant fabrics. While not wishing to be limited to any particular theory, it is presently believed that only relatively small molecules are capable of adequately penetrating the fabric surface and becoming permanently bonded to the fabric so that the fabric will withstand repeated launderings without significant loss of the coating composition. Moreover, it has been discovered that the use of non-aqueous solutions are critical to the formation of a permanently impregnated fabric. Aqueous solutions and/or emulsions, and particularly stabilized emulsions containing emulsifying agents do not result in a permanent bond with the fabric which will resist dissolution and delamination during laundering.

The utilization of polyurethane pre-polymers or partially polymerized polyurethanes has been found to be critical to obtaining treated fabrics having the desired wear and soil resistance properties without producing levels of fabric stiffness and harshness of hand which would make the garments unacceptable to the wearer. Any of the wide variety of well known polyurethanes and compounds which combined to form polyurethanes may be employed in the compositions of the invention. Typical polyurethane polymers and pre-polymers useful in the invention are those derived from the reaction of aromatic or aliphatic isocyanates such as toluene di-isocyanate, diphenylmethane 4,4 di-isocyanate and 1,6 hexamethylene di-isocyanate with compounds containing active hydroxyl, amino or carboxyl groups and combinations thereof, e.g. alcohols, glycols, esters, and the like although the polymers and pre-polymers of the invention may be derived from any of the other well known reactions for the production of such materials.

As previously noted, the use of a polyurethane prepolymer represents the preferred form of the invention since it has been found that more permanent impregnation of the garment fabric is achieved with smaller molecules. However, the novel compositions of the invention can employ partially polymerized low molecular weight polyurethanes, e.g. those having a molecular weight in the range of 1,000 to 3,000, preferably 1500 to 2500.

The use of selected fiuorocarbons in solution with the polyurethanes is also critical to the invention. These fluorocarbon compounds are well known in the art and one type of fluorocarbon useful in this invention is described in U.S. Pat. No. 2,803,615, issued Aug. 20, 1957 and assigned to Minnesota Mining and Manufacturing Company. This patent describes fluorocarbon acrylate and methacrylate esters and polymers thereof which include a perfluorocarbon tail which is a perfluoroalkyl group containing 4 to 12 carbon atoms. The preferred fluorocarbon compounds of the invention are those which combine both oil repellancy and soil release properties. These fluorocarbons are co-polymers formed from a reaction between the monomers described in the aforesaid patent with a hydrophilic monomer, preferably a straight or branched chain aliphatic material having a hydrophilic functional group such as NH SO H, COO OH- or a poly-oxyethylene chain, in which copolymerization occurs through the acrylic linkage of the fluorocarbon segment. A general formula for such copolymer may be described as follows:

Where R =perfluoroalkyl group containing greater than four fully fluoronated carbons.

R=alkylene bridging group containing usually one to twelve carbons.

R'=short chain alkyl group containing one to six carbons.

R"=hydrophilic monomer.

One such fluorocarbon composition useful in the preparation of the composition of this invention is commercially available under the trademark Scotchgard FC 218 from Minnesota Mining and Manufacturing Company and is an aqueous emulsion of a segmented copolymer having a hydrophilic segment and a segment containing long chain perfluoroalkyl groups.

The compositions of the invention are further characterized by the fact that they are non-aqueous solutions of the above described urethane polymers or pre-polymers and the fluorocarbon co-polymers. The formation of such solutions is critical to obtaining the maximum permanence of bond between the composition and the garment fabric.

It has now been discovered that a combination of mutually compatible solvents is critical to achieving a true non-aqueous solution of the polyurethane and fluorocarbon components of the fabric treating composition since these materials are not soluble in the same solvents. In accordance with the invention, the polyurethane component of the composition is dissolved in an aromaticaliphatic solvent mixture comprising an aromatic solvent containing 6 to 12 carbon atoms e.g. benzene, toluene, xylene and the like and an aliphatic alcohol containing 1 to 4 carbon atoms, e.g. methanol, ethanol, isopropanol and the like. Ordinarily the solvent employed to dissolve the polyurethane or polyurethane pre-polymer will comprise to 20 volume percent of the alcohol, preferably 10 to vol. percent alcohol and 80 to 100% of the aromatic solvent, preferably 85 to 90 volume percent. In one preferred embodiment the solvent is a mixture comprising 88% toluene and 12% isopropyl alcohol.

The fluorocarbon component of the composition is not soluble in the aromatic solvents. However, it has been discovered that a true solution of the composition of the invention can be obtained by dissolving the fluorocarbon in an aliphatic alcohol containing 1 to 4 carbon atoms, e-gm t a etha ol and i p opa q a d h a te combining this solution with the solution of the polyurethane component.

The total amounts of solvents employed to form the final composition is not critical with the exception that a suflicient amount of solvent must be employed to achieve the actual dissolution of the polyurethane and fluorocarbon components. Ordinarily the final composition will comprise 4 to 10 wt. percent, preferably 4 to 5 wt. percent of the polyurethane component, 1 to 5 wt. percent and preferably 1.2 to 3 wt. percent of the fluorocarbon component. The remainder of the composition will be a mixture of the aforesaid solvents in amount suificient to achieve an actual solution.

Although the above described composition may be employed directly as a fabric spray composition, in a preferred embodiment only that amount of solvent actually needed to achieve solution is employed and the balance of the solution will comprise a compatible volatile spray component. The use of such a diluent has been found to be desirable both from a safety standpoint and because the use of a rapidly evaporating diluent assists in assuring uniform fabric impregnation. The invention is not limited to the use of a particular diluent, although trichlorethylene is preferred.

The novel treated fabrics of the invention, and particularly shirt collars and neck bands are prepared by a method which comprises selectively spraying the surfaces of the upper portion of the shirt with the novel composition of the invention; evaporating a substantial portion of the volatile solvent portion of the spray composition; and subjecting the shirt collar to heat and pressure e.g. by ironing, or pressing thereby causing the in situ polymerization of the urethane and fluorocarbon components which results in a permanent bond between these polymers and the fabric fibers.

In the preferred method of the invention, each shirt collar is sprayed with 2 to 5 cubic centimeters of the composition, the volatile solvents are driven off and the collar is contacted with a conventional collar pressing machine comprising a padded buck and a heated metal pressing head which automatically presses against the padded buck, at temperatures ranging from 340 to 380 F., preferably 360 to 380 F. for a period of time ranging from 5 to 25 seconds, preferably 15- to 20 seconds at pressures ranging from 10 to 25 p.s.i., preferably 15 to 20 p.s.i. The method of the invention is preferably employed on fabric blends which include synthetic fibers, e.g. 10-80 wt. percent polyester fibers.

A wide variety of equipment may be used to carry out the method of the invention. A shirt manufactured in the normal fashion may be carried through a spray booth by a conveyor system, e.g. a pair of endless belts having the collar protruding therebetween so that the upper belt acts as a mask and only the surface layer of the collar fabric and the neck band are exposed to the spray. The spray booth may be equipped with a series of stationary nozzles which follows the movement of the shirt through the spray booth.

It is a further feature of the invention that the use of a spray technique permits hte selective application of the composition in such a fashion that the area of the collar which receives the greatest Wear also receives the greatest concentration of the spray composition. Thus, in the preferred embodiment, the entire surface of the collar will be coated with the composition but that portion of the surface on either side of and immediately adjacent to the point of connection of the collar to the neck band will have a greater concentration of spray than the remainder of the collar surface. Preferably those portions of the collar will contain 30 to e.g. 50% more of the composition than the remainder of the collar. Thus, the novel composition and method of the invention make it possible to provide the collar with the maximum amount of wear-life with a minimum increase in collar fabr c s lli ess.

The invention will be further understood by reference to the following illustrative examples.

EXAMTLE I A polyurethane pre-polymer was formed by mixing 5 parts by weight of 1,6-hexarnethylene di-isocyanate with 95 parts by weight of castor oil, a multifunctional polyester. The pre-polymer was dissolved in a solvent system comprising 88 vol. percent toluene and 12 vol. percent isopropyl alcohol. The above solution was diluted with trichloroethylene to yield a final solution comprising 90 vol. percent trichlorethylene and vol. percent of the urethane pre-polymer-toluene-isopropyl alcohol solution.

A solution consisting of 1.5 parts by weight of Scotchgard PC 218, an aqueous emulsion of a fluorocarbon co-polymer, was dissolved in 6 parts by weight of isopropyl alcohol. Five parts of this solution were dissolved in the trichloroethylene diluted urethane pro-polymertoluene-isopropyl alcohol solution.

The combined solution was employed as a spray composition for the surface layer of a shirt collar and neck band as follows: A shirt collar attached to a completed shirt was extended between two endless belts such that only the interior surface of the collar was exposed to a spray. The belts passed beneath a spray unit having nozzles designed to ride along a rail as the collar passed through the spray booth. The noozles were arranged so that the area of the collar surface immediately adjacent to the neck band received a greater concentration of spray than the remainder of the collar fabric surface.

The sprayed shirt was moved from the spray booth to a second conveyor where the volatile solvent and diluent were evaporated from the fabric. A hooded exhaust system extending over the conveyor assisted in the evaporation process.

The shirt collar was pressed using a conventional collar pressing machine at a temperature of 360 F. and a pressure of 15 p.s.i. for a period of 12 seconds to cause the in situ polymerization of the urethane and fluorocarbon components of the composition.

The shirts treated as described above were subjected to wear and laundering tests to determine their wearlife in comparison to untreated shirts. Two hundred (200) persons were used as subjects for this test. Each subject wore shirts made of a fabric comprising 65% ployester and 35% cotton which were either untreated or treated in accordance with this example. Each shirt was laundered after each wearing.

Upon completion of the tests the shirts were examined. The untreated shirts had pilled and stained to the point where they were considered worn out after 3-10 cycles (1 cycle=1 wearing-I-laundering). The shirts treated in accordance with this example were still wearable after 1220 cycles and had not pilled or stained.

It will readily occur to those persons skiled in the art that many modifications can be made Without departing from the spirit of the invention. Thus, other fabric treating agents known in the art, to the extent that they form compatible solutions with the composition of the invention may be employed. Moreover, the composition and method can be used to treat entire garments in instances where higher levels of fabric stiffness can be tolerated.

Having thus described the general nature as well as specific embodiments of the invention, the true scope will now be pointed out in the appended claims.

What is claimed is:

1. A composition for treating fabrics to enhance wearlife comprising a non-aqueous solution of a copolymer which is the reaction product of a fluorocarbon ester monomer and has the general formula:

where R; is a perfiuoroalkyl group containing greater than four fully fluoronated carbons, R is an alkylene bridging group containing usually one to tweleve carbons, R is a short chain alkyl group containing one to six carbons, and R is a straight or branched chain aliphatic material having a hydrophilic function group, and a polyurethane pre-polymer in a solvent system comprising an aromatic hydrocarbon having 6 to 12 carbon atoms and an aliphatic alcohol having 1 to 4 carbon atoms.

2. The composition of claim 1 in which said nonaqueous solution includes 1 to 5 wt. percent of said copolymer and 4 to 10 wt. percent of said urethane prepolymer.

3. The composition of claim 1 wherein said urethane pro-polymer has a molecular weight in the range of about 1000 to 3000 and comprises an isocyanate and a compound having at least one functional group selected from the group consisting of hydroxyl, amino and ester groups and combinations thereof.

4. The composition of claim 1 wherein said solvent system comprises to volume percent of said aromatic solvent and 10 to 15 volume percent of said aliphatic alcohol.

5. The composition of claim 4 wherein said aromatic solvent is toluene and said aliphatic alochol is isopropyl alcohol.

6. The composition of claim 1 further including a compatible diluent.

7. The composition of claim 6 wherein said diluent is trichloroethylene.

References Cited UNITED STATES PATENTS 3,533,977 10/1970 Read 260859 R 3,491,067 1/1970 Sellet 117139.5 A 3,474,061 10/1969 Bonin 26033.8 UB 3,528,849 9/1970 Vullo 117-1395 A 3,547,894 12/1970 Smeltz 117l39.5 A 3,255,030 6/1966 Storti 117--l39.5 A 3,385,812 5/1968 Brachman 260859 R 2,929,800 3/1960 Hill 26032.6 N 3,180,853 4/1965 Peters 260859 PV 3,256,231 6/1966 Johnson 26029.6 F 2,803,615 8/1957 Ahlbrecht 26029.6 F

MORRIS LIEBMAN, Primary Examiner P. R. MICHL, Assistant Examiner US. Cl. X.R.

117--139.5 A; 260334 UR, 33.6 F, 33.8 F, 859 R 

